Andrew Moore has an interesting editorial in the last issue of Bioessays:

The long sentence: A disservice to science in the Internet age

I cannot say that I agree with it 100%. I myself tend to favor longer sentences, as I feel that some subtlety of meaning and intonation can get lost when a long sentence is cut up.  And there should be some room for scientese in science.  But there’s no doubt that clarity is the first and foremost duty of a writer. There–I used “but” to start my sentence! Andrew Moore would be proud.